The proliferation of relatively non-invasive arthroscopic surgical procedures to repair joint and soft tissue injuries and ailments has significantly reduced the duration of post-operative hospital stays for patients of orthopedic surgeries. In many cases the arthroscopic surgical procedures have eliminated altogether the need for post-operative hospital stays. As a result, the bulk of post-operative recovery time from arthroscopic surgical procedures is typically spent in the home. The patient benefits from the familiar surroundings of the home, but usually lacks continuous access to a health care practitioner, which a hospital is able to provide. Nevertheless, it is generally incumbent that the patient receive immediate rehabilitative treatment following a surgical procedure on a joint or soft tissue, particularly when the joint or soft tissue is associated with the elbow or shoulder. The object of the rehabilitative treatment is to restore full range of motion to the involved joint, such as the elbow or shoulder, as soon as possible after a surgical procedure. Such rehabilitative treatments commonly include range of motion exercises which involve controlled movement of the arm without bearing substantial weight or placing an excessive force load on the elbow or shoulder. Unfortunately, the patient often cannot effectively perform such range of motion exercises without external assistance.
Automated motor-driven devices have been developed to assist post-operative patients when performing range of motion exercises with the goal of rehabilitating a joint and restoring range of motion to the joint in the absence of direct assistance from a health care practitioner. Such devices are termed continuous passive motion devices. For example, a continuous passive motion device for rehabilitation of the shoulder is disclosed in U.S. Pat. No. 5,179,939 to Donovan et al. The device moves the arm through a range of motion to simulate operation of the soft tissue and joint associated with the shoulder. It is a stated objective of the continuous passive motion device disclosed in U.S. Pat. No. 5,179,939 to Donovan et al. to allow the involved shoulder to follow a natural anatomical range of motion when the associated arm is moved through the range of motion. Nevertheless, the continuous passive motion device of U.S. Pat. No. 5,179,939 is relatively ineffective for this intended purpose because the linkage between the arm holder and drive motor is rigid, which limits the adaptability of the device to the varied anatomies and treatment requirements of each different patient. Furthermore, the continuous passive motion device of U.S. Pat. No. 5,179,939 requires careful anatomical alignment of the arm holder with the arm of the patient and strict monitoring of the motorized external force loads applied to the shoulder via the arm to prevent injury to the shoulder during rehabilitation thereof. Accordingly, the device is relatively complex for an inexperienced user to properly set up and operate, thereby requiring professional oversight which negates the goal of unassisted treatment.
As such, it is an object of the present invention to provide a continuous passive motion device for rehabilitation of a shoulder or elbow which is relatively simple to set up and operate, yet which is adaptable to a variety of patient anatomies and treatment requirements. More particularly, it is an object of the present invention to provide a continuous passive motion device for rehabilitation of a shoulder or elbow which is readily adaptable to different patient anatomies without requiring careful anatomical alignment of the device with the elbow or shoulder. It is a further object of the present invention to provide such a continuous passive motion device which can apply a motorized force to the elbow or shoulder for range of motion exercise thereof with a relatively low risk of injury. It is still another object of the present invention to provide such a continuous passive motion device which can be effectively operated by a patient lacking any specific medical knowledge, skill or experience with little or no oversight by a health care practitioner. It is yet another object of the present invention to provide such a continuous passive motion device which is fully self-contained and portable so that the device can be used by the patient in the home or other normal locales.
These objects and others are accomplished in accordance with the invention described hereafter.